Supplements in the News

Cocoa May Fight Hypertension

Published Wednesday, August 1, 2007

COLOGNE,
Germany - Consumption of moderate amounts of polyphenol-rich dark
chocolate approximately 30 calories a day may help reduce above optimal
blood pressure (BP) without affecting body weight, according to a new
study in JAMA
(2007;298(1):49-60). Researchers from University Hospital of Cologne
enrolled 44 adults aged 56 to 73 years old with untreated upper-range
prehypertension or stage 1 hypertension without concomitant risk
factors in the randomized, controlled, parallel group trial. For 18
weeks, participants received either 6.3 g/d of dark chocolate with 30
mg of polyphenols or matching polyphenol-free white chocolate. The
primary outcome measure was change in BP, with secondary outcomes of
changes in plasma markers of vasodilative nitric oxide (NO) and
oxidative stress, plus bioavailability of cocoa polyphenols. From
baseline to 18 weeks, dark chocolate intake reduced mean systolic BP by
-2.9 (1.6) mm Hg, and diastolic BP by -1.9 (1.0) mm Hg, without changes
in body weight, plasma levels of lipids, glucose or oxidative stress.
Hypertension prevalence declined from 86 percent to 68 percent. The
decrease in blood pressure was accompanied by an increase in markers of
NO and the appearance of cocoa phenols in plasma. White chocolate
intake had no effect on BP, NO or oxidative stress markers.

"Although the magnitude of the BP reduction was small, the effects
are clinically noteworthy. On a population basis, it has been estimated
that a 3-mm Hg reduction in systolic BP would reduce the relative risk
of stroke mortality by 8 percent, of coronary artery disease mortality
by 5 percent, and of all-cause mortality by 4 percent," the authors
wrote. "The most intriguing finding of this study is that small amounts
of commercial cocoa confectionary convey a similar BP-lowering
potential compared with comprehensive dietary modifications that have
proven efficacy to reduce cardiovascular event rate. Whereas long-term
adherence to complex behavioral changes is often low and requires
continuous counseling, adoption of small amounts of flavanol-rich cocoa
into the habitual diet is a dietary modification that is easy to adhere
to and therefore may be a promising behavioral approach to lower blood
pressure in individuals with above-optimal blood pressure."